Field of the Invention
The present invention relates to the manufacture of nonwoven materials and, more particularly, to a new and improved method and apparatus for producing nonwoven materials of any suitable thickness and/or composition.
Description of the Background Art
At the present time, substantially all needle looms for producing nonwoven materials such as felt have a maximum opening between the stripper plate for the needles and the upper surface of the supporting bed having holes for receiving the needles of about 3½ inches. Accordingly, the maximum thickness of needle felts produced by existing needle looms is about 1¾ inches and the maximum density is about 170 oz per square yard of product. This is because the number and pattern of needles is limited for the reason that the present needle looms are constructed so that the needles pass through the product to be needled and into aligned openings in the upper surface of the supporting bed. The number and pattern of needles, therefore, is limited by the pattern of openings in the supporting bed.
Current needle looms are constructed so that the vertical movement of the needle bed is limited to 1 9/16 inches to 3 inches.
Also, the speed of the material being advanced through the current needle looms is limited by the fact that the needles extend through the material into the openings in the supporting bed. Because the needles enter the openings in the supporting bed, they are subject to breakage if, for some reason, they are not properly aligned with the openings in the support bed.
As a result of the current needle loom constructions, the production of needle felts or nonwoven materials is limited to materials of small thickness, such as 1¾ inches maximum and this limitation limits the uses of such needle felts or nonwoven materials.
A need has risen, therefore, for a new and improved method and apparatus for producing needle felts and other nonwoven materials that can be used for any suitable or desired applications. The present invention meets this need and allows the creation of any density or oz per sq yd to any thickness requirement above the standard needling of 170 oz per sq. yard and 1¾″ thick. It also allows any desired or suitable synthetic fibers to be added to needle felts throughout the build, such as, e.g., ceramic fiber, high-purity alumina, zirconia, silica spun ceramic fibers or a base rayon viscose or cellulose base product prior to carbonization.